Soft-headed hammer



W K JAHN ET AL SOFT-HEADED HAMMER Flled March 12 1946 June 24, 1.952

Patented June 24, 1952 SOFT-BEADED HAMltIER` Walter K. Jahn, Beverly Hills, Joseph A. Carmien,

Los Angeles, and John E. Mullngs, Pacific Palisades, Calif., assignors to New Plastic Corporation, Los Angeles, Calif., a corporation of California Application March 12, 1946, Serial No. 653,792

4 Claims. (Cl.`14536) This invention relates to hammers, and particularly a type of hammer that includes a relatively soft head that impinges upon a body when struck by the hammer. Hammers of this type are used very largely for delivering a blow to a part without any danger of marring the surface struck. They perform a function that was formerly performed largely by a lead maul, that is, a mallet or hammer in which the head was formed of soft lead, and which could strike a harder metal part without defacing it.

One of the objects of this invention is to provide a hammer or mallet for performing this function, having a percussion head of relatively soft material for imparting a blow, particularly adapted to be formed of a plastic material in which the inner end of the percussion head is seated against the end of the hammer head, and to provide a construction enabling the percussion head to be detachably mounted on the hammer body, and at the same time, functioning so as to substantially protect the seated' end of the plastic percussion head from distortion occurring in the percussion head when the blow is struck.

In its preferred form, the invention includes a hammer body with a tapered socket to receive a relatively soft or yielding percussion head, and one of the objects of Vthis invention is to provide a correlated form for the socket and the percussion head, that will operate to prevent dislodgement of the head from its socket when in use.

In its preferred embodiment, the invention includes a hammer body of rigid material having an end face at which a socket is formed to receive the inner end of a relatively soft percussion head; and one of the objects of the invention is to provide an improved construction for this percussion head, and for effecting its removable attachment to the hammer body.

Further objects of the invention will appear hereinafter.

The invention consists in the novel parts and combination of parts to be described hereinafter, all of which contribute to produce an eilicient plastic headed hammer.

A preferred embodiment of the invention is described in the following speciiication, while the broad scope of the invention is pointed out 4in the appended claims.

In the drawings:

Fig. 1 is a side view showing a hammer embodying the invention, partially in elevation, and partially in section on its longitudinal axis. -This view also shows a portion of the handle material under high pressure.

2 and shank in cross-section, and shows the lower end of the handle broken away.

Fig. 2 is a cross-section taken on the line 2-2 of Fig. 1, particularly illustrating the location and the relatively large area of a baille head that is employed to protect the socketed end of the percussion head from distortion when a blow is struck with this hammer.

Before proceeding to a more detailed description of this invention, it should be stated that in accordance with this improvement a relatively soft percussion head is provided with means for detachably securing it to the end of the hammer body. This percussion head is adapted to be formed as a molding in a plastic mold, of plastic In accordance with this invention, a baffle head is provided in the percussion head disposed in a plane transverse to the longitudinal axis of the hammer body, and this baille head is located at a considerable distance back of the percussion face of the percussion head. It also has considerable area, so that compression and distortion of the material between the percussion face and this baille, is substantially confined to the area of this baille head. In other words, although there is an annular zone of material of the percussion head located beyond the margin of the baille head, the percussion developed by striking a blow with the hammer, is substantially prevented from forming any considerable compression in this peripheral zone. In this way the baille head shields the inner portion of the percussion head so that the distortion effects developed in the inner portion or socketed portion of the percussion head, are reduced to a minimum. A secondary and desirable effect is that by this same means the original shape of the percussion head is substantially maintained throughout the life of the percussion head, after which the percussion head may be removed and replaced. by 'a new and unworn percussion head, it being understood, of course, that in due time these percussion heads tend to lose their shape and effectiveness.

Referring more particularly to the embodiment of this invention illustrated. I indicates a body which, in the present instance, is of substantially cylindrical form. Its end walls have outer faces 3 against which the percussion heads 4 and 5 seat, and at these end faces it is preferable to provide sockets 6, respectively, in lwhich the inner ends of the percussion heads 4 and 5 are received. For this purpose the sockets 6 are preferably of substantially conical form, butin position, and at the same time. .toprovide means for protecting the socketed end of theV same from too great a degree of distortion when a blow is struck with the hammer, it is preferable to employ a bafe head 9 which isV in the form of a disc with a forward dat face l) that is disposed in a plane substantially at right angles to the longitudinal axis of the hammer body l. This baffle'- is preferably formed with a stem or stud I l that has a threaded end l2 thatl projects from the head and is received. in a threaded opening |13: formed' in the corresponding end face of the hammer body.

In order to prevent relative rotation between the stem |.IY `and the percussion heads, it. is preferable toprovide substantially radially disposed uns or wings Illv that project' out from the stem.

These-.wings may be made as. long as necessary to enable them to prevent. relative rotation of the stem and: the percussion head. Their length will Vdepen-df largelyV upon the character of the material; out of which the percussion heads. are formed; the softer this material, the longer these fins' should be.

The bafe headI 9 asillustrated in Fig.. 2, is preferabl'y of considerable diameter as compared with that of the percussion head. This is indi:-

cated in Fig; 2 as well as in Fig. 1.v From an i`n spection of Fig; 2, it willv bei evident that a narrow peripheral annular zone is formed in the materialy Voi Y the ypercussion head 5, through which' it might be' possibleV to impart compres-- sion arising in. thel percussion head when the blowI is. struck, but in. order to reduce this compression to la minimum, it is preferable to form the percussion head 5 with a crowned or rounded percussion faceV f5. This face is` struck' with a radius havinga center located sov that a line such as the line liliy drawn normal to this crown face would, if extended, impinge upon the forward surface of the disc 9. Hence, although nearly all blows struck: with this hammer would be necessari-lylocated` quite near the longitudinal axis of the percussion head, even if a blow were struck with a hammerV near the. edge of the face l5, no direct compression would occur in the extreme periphery or'the superficial' surface of the perhead.; Vand' furthermore, such an eccentrically located impingement would result in eftectingA a compression of the. material of the percussion head between the point struck and the forward face of the baliie head E, which would result in a tendency to cause an outward movement of this material in a general radial direc- .,tionf, which of course would counteract or disperse compressive forces in the peripheral' zone referred to.

In practice, it is preferable to mold the stein or studli and its: integral baffle head s directly in 'the molded plastic. The threads of the threaded extension i2' would, of course, be chased on the stem. before: setting this metal part in the mold preparatory to they molding operation. The

4 taper on the abutment 8 is formed on a different degree from that of the socket. It is preferably blunter, that is, less acute than the degree of taper of the conical surface 6. In other words, the conical surface on the side of the abutment 8\ is preferablyconstructed so that the elements of this conical surface subtend a greater angle than the elements of the conical surface 6. This will cause the development of considerable pressure between these two conical surfaces in the vicinity of the shoulder l, and this concentration4 of pressure at this point, will increase the eiiectiveness` of the forces developed in this way, to resist tendencies of the percussion heads to work loose when in. use.

The hammers weight may be controlled by making its body of different metals having different specic gravities. Any metal or hard plastic material that is adapted to be molded can be used readily for this purpose. The hammer body has atapered eye I8 that receives a tapered tip orrnose Z on the end of the handle I7, and a shoulder 22 Yis formed on the handle to seat against' the hammer body adjacent the larger end of the eye. A transverse pin 2| can be driven into a hole drilled through the side of the body i'- while the tip 29 is in place. This pin can have its ends riveted over to prevent its working out of itsV hole, or other means may be employed for securing it in position. y

It will be evident that when a percussion head such as described, is being screwed onto the end of' the hammer body, its conical abutment will become compressed against the conical sideface of the socket that receives it;Y and the frictional contact between the conical surfaces will develop a drag or circumferential distortion effect at the periphery of' the abutment. When blows are struck with the hammer, this circum-` ferential distortion will finally become reduced, with a consequent increase in the outward pressure of the confined material in a radial direction. In other words, the forces developed at the periphery, will cause an increase in the resistance to loosening of` the head due to vibrations caused by the blows.

Many other embodiments of the invention may be resorted to withoutV departing from the spirit of the invention.

We claim as our invention:

l'. A hammer head having a rigid body, a per-V cussion head of yielding cushion material seated on said body and having a percussion face on its outer end, a baiile head in the form of a disc embedded in the cushion material of said head and extending transversely therein behind the percussion face, and a Vstem Vconnecting said baffle head to said rigid body, said disc operating to absorb a portion of the force developed in the percussion head when a blow is struck with the hammer at the percussion face.

2. A hammer according to claim l, in which the hammer body includes a socket on. its end vto receive the percussion head, said. socket located opposite the percussion face; and in which the entire percussion head is composedv of a yielding cushion material that extends. into the said socket in the hammer body, said baille head operating as a shield for the inner portion of the yielding cushion material of the percussion head so as to reduce the distortion thereof when a blow is struck by the hammer.

3. A hammer according to claim l, including Y means associated with the said stem and projecting in a Ygeneral radial direction therefrom for preventing relative rotation between the stem and the percussion head.

4. A hammer head having a rigid body with a socket on its end, a percussion head of yielding cushion material having a percussion face at its outer end, and having its inner end received in said socket, a baille-head in the form of a disc embedded in the cushion material of said head and extending transversely therein behind the percussion face, a stem embedded in the cushion material of the percussion head and projecting outwardly from the same at the inner end of the percussion head, the end of said stem having threads thereon; said body having a threaded hole at the bottom of said socket to receive the threaded stem, said stem being con-l nected to said baffle head, and means associated with said disc and said stern to prevent relative rotation of the percussion head and stem,

6 and enabling rotation of the percussion head to screw the end of the stem into the threaded hole to seat the inner end of the percussion head in its socket.

WALTER. K. JAHN. JOSEPH A. CARMIEN. JOHN E. MULLINGS.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 918,060 Kabureok Apr. 13, 1909 974,021 Blake Oct. 25, 1910 1,250,959 Brown Dec. 25, 1917 1,839,835 Cook Jan. 5, 1932 2,377,157 Kindland May 29, 1945 

